The Study of Dielectric Properties of Some Ionic Liquids Based on Imidazolium by Dielectric Spectroscopy and Data Mining

AbstractIonic liquids (ILs) are liquid salts of differentiating to all molten salts with temperature below 100° C (arbitrarily set with reference to the boiling point of water), but a large number of them are liquids at room temperature. The properties of ionic liquids such as their wide field of electro activity, their high conductivity, and high thermal stability have made them new prime candidates in searching for a new energy systems (photovoltaic cell, battery, solar concentrator ...). The present work objective is to study the physicochemical properties of some ionic liquids based on imidazolium ([BMIM]+ [BF4]-, [BMIM]+[PF6]-, [HMIM]+ [Br] -,[BMIM]+ [Br]−) and more particularly the dielectric properties. We performed measurements by dielectric spectroscopy to see the influence of the size of the anion and the length of the alkyl chain of the cation on the conductivity of ionic liquids at different temperatures. We made also theoretical study by using data mining techniques such as the analytical method principal components (PCA), that help us to study the relationships between variables (σ RT (S / m), Tg (K) lnσ∞ (S / m), B, T0 (K), m) and their relation with ionic liquids structure